Modeling material for forming photofabrication model in ink-jet three dimensional printing, supporting material for supporting the shape of photofabrication model on photofabrication and production method of photofabrication model

ABSTRACT

The present invention aims to provide a supporting material for supporting the shape of a photofabrication model on photofabrication in ink-jet three dimensional printing method in which the photocured product is excellent in solubility in water and is easy to remove after photofabrication, and the like. A modeling material for forming a photofabrication model in ink-jet three dimensional printing method containing a curable resin component with a weighted average of SP value of 9.0 to 10.3; and a supporting material for supporting the shape of a photofabrication model on photofabrication in ink-jet three dimensional printing method containing a water-soluble monofunctional ethylenically unsaturated monomer (F), polyoxypropylene glycol with a number average molecular weight of 100 to 5,000 and/or water (G), and a photopolymerization initiator (D).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/868,157, filed Apr. 23, 2013, which in turn is acontinuation of PCT/JP2011/073778, filed Oct. 17, 2011, which claimsforeign priority based on Japanese Patent Application No. 2010-244909,filed Nov. 1, 2010 and Japanese Patent Application No. 2011-208389,filed Sep. 26, 2011, the contents of which is incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a modeling material for forming aphotofabrication model in ink-jet three dimensional printing, asupporting material for supporting the shape of a photofabrication modelon photofabrication, a two-pack photocurable resin composition forink-jet three dimensional printing, a photofabrication model obtained byallowing the composition to be photocured, and a production method of aphotofabrication model using the composition.

BACKGROUND ART

A method of irradiating a liquid photocurable resin with light such as alaser beam or ultraviolet rays to cure the resin in a given pattern andpreparing a design model or a working model in three dimensions has beenwidely known, and various resins have been proposed as the liquidphotocurable resin (see, for example, Patent Documents 1 to 6). Inrecent years, the three dimensional printing system employing an ink-jetmethod has been proposed, and compared with the conventional method, ithas been made possible to cure the liquid photocurable resin dischargedfrom an ink jet nozzle and to stack layers and carry out thephotofabrication. The three dimensional printing device has advantagesthat, for example, a large tank for the liquid resin and provision of adark room used in the conventional method are not necessary. It is madepossible to allow a photofabrication apparatus to be compact and becomesmaller, and by employing a CAD (Computer Aided Design) system, theapparatus has been attracting attention as a 3-D CAD system capable offreely preparing a stereo model (see, for example, Patent Document 7).

Moreover, not limited to the three dimensional printing system employingan ink-jet method, a method of carrying out the photofabrication using amodeling material forming a photofabrication model and a supportingmaterial supporting the shape of the photofabrication model onphotofabrication has also been known in order to fabricate aphotofabrication model having a complex shape (see, for example, PatentDocuments 8 and 9). Furthermore, in the photofabrication employing anink-jet method, a method of preparing a photofabrication model using aspecific modeling material and a specific supporting material has alsobeen proposed (see, for example, Patent Documents 10 to 13).

PRIOR ART DOCUMENT Patent Document

Patent Document 1: Japanese Patent Laid-Open No. 1-204915

Patent Document 2: Japanese Patent Laid-Open No. 8-59760

Patent Document 3: Japanese Patent Laid-Open No. 9-169827

Patent Document 4: Japanese Patent Laid-Open No. 9-316111

Patent Document 5: Japanese Patent Laid-Open No. 2001-310918

Patent Document 6: Japanese Patent Laid-Open No. 2004-59601

Patent Document 7: Japanese Patent Laid-Open No. 2002-67174

Patent Document 8: Japanese Patent Laid-Open No. 2002-178412

Patent Document 9: Japanese Patent Laid-Open No. 2004-255839

Patent Document 10: EP Patent No. 1274551B1

Patent Document 11: EP Patent No. 1741545A2

Patent Document 12: Japanese Patent Laid-Open No. 2010-155889

Patent Document 13: Japanese Patent Laid-Open No. 2010-155926

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, in a method of irradiating a resin with a laser beam,ultraviolet rays or the like to carry out the photofabrication, althoughthe resin is generally irradiated with a laser beam, ultraviolet rays orthe like from the upper side or lower side of the liquid level of aliquid photocurable resin while moving the liquid level up and down toprepare a photofabrication model, in general, such an apparatus has notbeen widely prevailing and the number of apparatus installed has beenrestrictive because there are problems that it is necessary to provide adedicated dark room since the liquid photocurable resin is cured alsowith light from outside and the like, only a portion of the liquidphotocurable resin is used for the preparation of the photofabricationmodel, and further, the cost of equipment becomes very expensive sincevarious incidental facilities are required for the photofabrication.

Moreover, with regard to the ink-jet method, the above-mentionedproblems can be alleviated, but there is still a problem in the casewhere a photofabrication model with a complex shape is prepared. Thatis, in the method, although it is necessary to use a modeling materialand a supporting material in combination, for example, in the methodsdisclosed in Patent Documents 10, 11, 13 and the like, the viscosity,the surface tension and the physical properties of a modeling materialor a supporting material are taken into consideration, but there is aproblem that the working accuracy cannot be maintained because aphotofabrication model obtained by allowing a modeling material to becured is deformed due to swelling on removing a supporting material bywashing with water or the like after photofabrication.

Moreover, with regard to the supporting material, in the methodsdisclosed in Patent Documents 10 and 11, there are problems that ittakes time to remove the supporting material, and it is difficult toremove the supporting material in all details because a crosslinked gelin which the supporting material basically forms a bond with a modelingmaterial is formed. With regard to the supporting material disclosed inPatent Document 12, it is basically difficult to allow the supportingstrength and the solubility in water to be compatible, and there areproblems that it takes a lot of time to remove the supporting materialafter curing of a modeling material, and that the supporting strengthcannot be maintained when reduction in the concentration of acrylamideswith an acryloyl group and increase in the amount of a chain transferagent are made. Furthermore, in the conventional technique described inthe known document, no consideration is paid to a problem that ondischarging a modeling material and a supporting material by an ink-jetmethod, both intermix by the end of curing and the intermixed part isdeformed due to expansion when, for example, the photofabrication modelis immersed in water.

Means for Solving the Problems

As a result of extensive researches for solving the above-mentionedproblems, the present inventors have reached the present invention. Thatis, the present invention is directed to a modeling material for forminga photofabrication model in ink-jet three dimensional printing systemcontaining a curable resin component with a weighted average of SP valueof 9.0 to 10.3; a supporting material for supporting the shape of aphotofabrication model on photofabrication in ink-jet three dimensionalprinting system containing a water-soluble monofunctional ethylenicallyunsaturated monomer (F), an alkylene oxide adduct containing anoxypropylene group and/or water (G), and a photopolymerization initiator(D); a two-pack photocurable resin composition for ink-jet threedimensional printing system including a combination of a modelingmaterial for forming a photofabrication model in ink-jet threedimensional printing system and a supporting material for supporting theshape of the photofabrication model on photofabrication including theabove-mentioned modeling material as the modeling material and theabove-mentioned supporting material as the supporting material; aphotofabrication model obtained by allowing the above-mentionedcomposition to be photocured by ink-jet three dimensional printingsystem; and a production method of a photofabrication model by ink-jetthree dimensional printing system including the step of producing theabove-mentioned composition with a photofabrication apparatus.

Effects of the Invention

The modeling material, the supporting material, the two-packphotocurable resin composition, the photofabrication model prepared fromthe composition and the production method thereof according to thepresent invention produce the following effects. (1) There is verylittle swelling deformation of the modeling material due to water ormoisture absorption on photocuring and after curing. (2) The photocuredproduct of the supporting material is excellent in solubility in waterand it is easy to remove the product after photofabrication. (3) Withregard to the two-pack photocurable resin composition, the supportingmaterial is not compatible with the modeling material and thephotofabrication model has excellent mechanical properties. (4) Thephotofabrication model prepared from the two-pack photocurable resincomposition is excellent in working accuracy. (5) The production methodof the photofabrication model is excellent in productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a three-dimensional modeling systememploying an ink-jet method.

FIG. 2 is a schematic side view showing a configuration of athree-dimensional modeling apparatus.

FIG. 3 is a schematic plan view showing a configuration of athree-dimensional modeling apparatus.

FIG. 4 is a schematic view of one of printer heads, viewed from thelower part.

FIG. 5 is a schematic view of a materials supply system in which amodeling material and a supporting material are supplied to both printerheads respectively.

FIG. 6 is a schematic view showing the halfway state of athree-dimensional model prepared while operating a three-dimensionalmodeling apparatus.

FIG. 7(A) is a schematic view showing a model accompanied by supportingmaterials after the completion of forming, and FIG. 7(B) is a schematicview showing a model obtained by removing the supporting materials fromthe model accompanied by the supporting materials after the completionof forming.

MODES FOR CARRYING OUT THE INVENTION

The modeling material for forming a photofabrication model in ink-jetthree dimensional printing device according to the present invention ischaracterized as being a modeling material containing curable resiningredients (A) to (C) with a weighted average of SP value of 9.0 to10.3. [Modeling material] The weighted average of SP value (hereinafter,sometimes referred to simply as the SP value) of curable resiningredients (A) to (C) in the modeling material according to the presentinvention is 9.0 to 10.3, preferably 9.2 to 10.0. When the SP valueexceeds 10.3, the cured product of the modeling material is deformed dueto swelling with water in the case where it is immersed in water orwashed by water jet in order to remove the cured product of thesupporting material described later and the deformation is not resolvedeven after drying. If the cured product of the modeling material isallowed to stand, it absorbs moisture and is apt to be deformed.Moreover, when the SP value is less than 9.0, the cured product becomesbrittle and the toughness is lowered. The SP value of the curable resincomponent in the modeling material may be adjusted so as to fall in theabove-mentioned range by selecting the kind and content of the curableresin ingredients (A) to (C) which are described later and constitutingthe modeling material.

In this context, the SP means the solubility parameter and serves as arough indication for mutual solubility of materials. It is known thatthe smaller the difference of SP value between the materials is, thegreater the mutual solubility is. The SP value is determined by thefollowing equation.SP=[(ΔH−RT)/V]^(1/2)

In the equation, V: molar volume (cc/mol), ΔH: latent heat ofvaporization (cal/mol), and R: gas constant 1.987 cal/mol·K.

The SP value of a copolymer or a blend is calculated by the method whichis proposed by Fedors, et al. and described in the following document.With regard to the SP value of a copolymer or a blend, by assuming thatthe additivity rule holds in the method, the SP value of a copolymer andthe SP value of a blend are calculated as the weighted average of SPvalue by proportionally allotting the SP values of constituent monomersand the SP values of constituent ingredients, respectively on the basisof each constituent proportion (% by weight).

“POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2, RobertF. Fedors, pp. 147-154”

With regard to the modeling material according to the present invention,the curable resin component contains a monofunctional ethylenicallyunsaturated monomer (A), a polyfunctional ethylenically unsaturatedmonomer containing no urethane group (B), a urethane group-containingethylenically unsaturated monomer (C) and a photopolymerizationinitiator (D). In this context, the modeling material is designed sothat the weighted average of the SP values of the curable resiningredients in the modeling material, namely, (A) to (C), is 9.0 to10.3.

[Monofunctional Ethylenically Unsaturated Monomer (A)]

Although the monofunctional ethylenically unsaturated monomer (A) is notparticularly limited as long as it is a compound with an ethylenicallyunsaturated group [a (meth)acryloyl group, an N-vinyl group or thelike], from the viewpoint of making the SP value small, preferred is ahydrophobic monofunctional ethylenically unsaturated monomer (A1) (theSP value is not more than 10).

Examples of (A1) include linear or branched alkyl (meth)acrylates [acompound with 4 to 30 carbon atoms (hereinafter, abbreviated as C) suchas methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate,lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylateand t-butyl (meth)acrylate]; alicyclic (meth)acrylates [a C6 to C20compound such as cyclohexyl (meth)acrylate, 4-t-cyclohexyl(meth)acrylate, isobornyl (meth)acrylate and dicyclopentanyl(meth)acrylate]; and heterocyclic (meth)acrylates [a C5 to C20 compoundsuch as tetrahydrofurfuryl (meth)acrylate,4-(meth)acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane,4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane and adamantyl(meth)acrylate].

Among the above-mentioned examples of (A1), from the viewpoint ofenhancing the working accuracy enough to stand the forming temperature(50 to 90° C.) on curing of the modeling material and the viewpoint ofheat resistance of the photofabrication model itself to the operatingtemperature, further preferred are those that give the homopolymerthereof a high (50° C. or more) glass transition point (hereinafter,abbreviated as Tg), namely, methyl (meth)acrylate, ethyl (meth)acrylateand stearyl (meth)acrylate among alkyl (meth)acrylates, isobornyl(meth)acrylate and dicyclopentanyl (meth)acrylate among alicyclic(meth)acrylates, and adamantyl (meth)acrylate. Among these, from theviewpoint of photoreactivity, especially preferred are highly reactiveacrylates, namely, isobornyl acrylate and dicyclopentanyl acrylate amongalicyclic acrylates, and adamantyl acrylate.

In the case where the modeling material can be designed so that theweighted average of the SP values of the curable resin ingredients inthe modeling material, namely, (A) to (C), is not more than 10.3, awater-soluble monofunctional ethylenic unsaturated monomer (A2) may beincorporated as (A). In the present invention, “water-soluble” meansthat the solubility in water (25° C.) is not less than 1 (g/100 g ofwater).

Examples of (A2) include hydroxyl group-containing C5 to C15(meth)acrylates [hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like]; hydroxylgroup-containing (meth)acrylates with a number average molecular weight[hereinafter, abbreviated as Mn, measured by a gel permeationchromatography (GPC) method] of 200 to 2,000 [polyethylene glycol(hereinafter, abbreviated as PEG) mono(meth)acrylate,methoxypolyethylene glycol mono(meth)acrylate, polypropylene glycol(hereinafter, abbreviated as PPG) mono(meth)acrylate,methoxypolypropylene glycol mono(meth)acrylate, mono(meth)acrylate ofPEG-PPG block polymer and the like]; C3 to C15 (meth)acrylamidederivatives [(meth)acrylamide, N-methyl(meth)acrylamide,N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide,N-butyl(meth)acrylamide, N, N′-dimethyl(meth)acrylamide,N,N′-diethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide,N-hydroxypropyl(meth)acrylamide, N-hydroxybutyl(meth)acrylamide and thelike], acryloyl morpholine and the like.

The content of (A2) is usually not more than 10% on the basis of theweight of the modeling material, and from the viewpoint of reduction inwater-swelling ratio of a photocured product of the modeling materialdescribed later, preferably not more than 5%, further preferably notmore than 3% and most preferably 0%. The above-mentioned examples of themonofunctional ethylenically unsaturated monomer (A) may be used aloneor in combination of two or more thereof if necessary.

[Polyfunctional Ethylenically Unsaturated Monomer Having No UrethaneGroup (B)]

The polyfunctional ethylenically unsaturated monomer having no urethanegroup (B) is not particularly limited as long as it is a compound havingno urethane group and having two or more ethylenically unsaturatedgroups. By allowing (B) to be incorporated into the modeling material,it is made possible to enhance the mechanical strength and elasticmodulus of the cured product.

Although (B) is not particularly limited as long as it is a monomerhaving two or more (preferably 2 to 3) ethylenically unsaturated groupsin the molecule, from the viewpoint of making the SP value small,preferred is a hydrophobic polyfunctional ethylenically unsaturatedmonomer having no urethane group (B1) (the SP value is not more than10).

Examples of (B1) include linear or branched alkylene glycoldi(meth)acrylates [a C10 to C25 compound such as 1,6-hexane dioldi(meth)acrylate, neopentylglycol di(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate,2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate] and alicyclicdi(meth)acrylates [a C10 to C30 compound such asdimethyloltricyclodecane di(meth)acrylate].

Among the above-mentioned examples of (B1), from the viewpoint ofenhancing the working accuracy enough to stand the forming temperature(50 to 90° C.) on curing of the modeling material and the viewpoint ofheat resistance of the photofabrication model itself to the operatingtemperature, further preferred are those that give the homopolymerthereof a high (50° C. or more) glass transition point, namely,neopentylglycol di(meth)acrylate and 3-methyl-1,5-pentanedioldi(meth)acrylate among branched alkylene glycol di(meth)acrylates, anddimethyloltricyclodecane di(meth)acrylate among alicyclicdi(meth)acrylates. Among these, from the viewpoint of photoreactivity,especially preferred are highly reactive acrylates, namely,neopentylglycol diacrylate, 3-methyl-1,5-pentanediol diacrylate anddimethyloltricyclodecane diacrylate. The above-mentioned examples of thepolyfunctional ethylenically unsaturated monomer having no urethanegroup (B) may be used alone or in combination of two or more thereof ifnecessary.

[Urethane Group-Containing Ethylenically Unsaturated Monomer (C)]

The urethane group-containing ethylenically unsaturated monomer (C) is amonomer having one or more ethylenically unsaturated groups andcontaining a urethane group. By allowing (C) to be incorporated into themodeling material, it is made possible to give the cured producttoughness and to adjust the toughness and elongation of the curedproduct. Examples of (C) include a monomer formed from a compound havinga hydroxyl group and a (meth)acryloyl group (a) and a polyisocyanate(b), and from the viewpoint of making the SP value small, preferred is amonomer being hydrophobic (the SP value is not more than 10.9) (C1).

Examples of (a) include C5 or more compounds with an Mn of 5,000 or lesssuch as the following compounds, and a mixture of two or more kindsthereof. (a1): an alkylene oxide (hereinafter, abbreviated as AO) adductof (meth)acrylic acid (alkylene in AO has 2 to 4 carbon atoms) such as(meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid2-hydroxypropyl ester, (meth)acrylic acid 2-hydroxybutyl ester, and anadditional AO adduct thereof (molecular weight: 160 or more, Mn: 5,000or less); (a2): an ε-caprolactone adduct of (a1) (molecular weight: 230or more, Mn: 5,000 or less) such as a (meth)acrylic acid2-hydroxyethyl-ε-caprolactone 2-mole adduct; (a3): a reaction product of(meth)acrylic acid and a diol (Mn: 300 to 5,000) such asmono(meth)acrylate of a diol [Mn: 300 to 5,000, e.g. polycarbonate diol,PEG, polyester diol and the like];

(a4): a reaction product of (meth)acrylic acid and an epoxide (C8 toC30) such as 3-phenoxy-2-hydroxypropyl (meth)acrylate and3-biphenoxy-2-hydroxypropyl (meth)acrylate; (a5): a reaction product of(meth)acrylic acid and a 3 or more functional polyol (molecular weight:92 or more, Mn: 5,000 or less) such as glycerin mono- anddi(meth)acrylate, trimethylolpropane mono- and di(meth)acrylate,pentaerythritol mono-, di- and tri(meth)acrylate, ditrimethylolpropanemono-, di- and tri(meth)acrylate, dipentaerythritol mono-, di-, tri-,tetra- and penta(meth)acrylate, and an AO adduct thereof (number ofmoles added: 1 to 100); and among these examples of (a), from theviewpoint of toughness, preferred are (a1) and (a2).

Examples of the poly (di, tri or more) isocyanate (b) include aromaticpolyisocyanates [a C (excluding C in the NCO group, the same holds truefor description below) 6 to C20 compound such as 2,4- and/or2,6-tolylene diisocyanate (TDI) and 4,4′- and/or 2,4′-diphenylmethanediisocyanate (MDI)], aliphatic polyisocyanates [a C2 to C18 compoundsuch as hexamethylene diisocyanate (HDD], alicyclic polyisocyanates [aC4 to C45 compound such as isophorone diisocyanate (IPDI), 2,4- and/or2,6-methykyclohexane diisocyanate (hydrogenated TDI) anddicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI)],aromatic-aliphatic polyisocyanates [a C8 to C15 compound such as m-and/or p-xylylene diisocyanate (XDI) and α,α,α′,α′-tetramethylxylylenediisocyanate (TMXDI)], a nurate thereof, and a mixture thereof.

In the case where the urethane group-containing ethylenicallyunsaturated monomer (C) is produced, from the viewpoints of toughnessand elongation of the cured product, an ingredient (f) having a hydroxylgroup and no unsaturated group other than (a) may be incorporated as areactive ingredient. Examples of (0 include C1 or more polyhydricalcohols with an Mn of 3,000 or less (ethylene glycol, propylene glycol,glycerin, polyalkylene glycol and the like) and monohydric alcohols(methanol, ethanol and the like). Among these, from the viewpoint ofimpact resistance of the cured product, preferred are monohydricalcohols.

With regard to the Mn of (C), the lower limit is preferably 500, furtherpreferably 700 from the viewpoint of impact resistance of the curedproduct, and the upper limit is preferably 5,000, further preferably2,000 from the viewpoints of ease of handling of the composition andworking accuracy of the cured product.

The number of functional groups of the ethylenically unsaturated groupin (C) is preferably 1 to 20, further preferably 1 to 3 from theviewpoints of hardness and impact resistance of the cured product.

[Photopolymerization Initiator (D)]

Examples of the photopolymerization initiator (D) include benzoincompounds [a C14 to C18 compound such as benzoin, benzoin methyl ether,benzoin ethyl ether, benzoin propyl ether and benzoin isobutyl ether];acetophenone compounds [a C8 to C18 compound such as acetophenone,2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone,1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one,diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone and2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoprop an-1-one];anthraquinone compounds [a C14 to C19 compound such as2-ethylanthraquinone, 2-t-butylanthraquinone, 2-chloroanthraquinone and2-amylanthraquinone]; thioxanthone compounds [a C13 to C17 compound suchas 2,4-diethylthioxanthone, 2-isopropylthioxanthone and2-chlorothioxanthone]; ketal compounds [a C16 to C17 compound such asacetophenone dimethyl ketal and benzil dimethyl ketal]; benzophenonecompounds [a C13 to C21 compound such as benzophenone,4-benzoyl-4′-methyldiphenyl sulfide and4,4′-bismethylaminobenzophenone]; phosphine oxide compounds [a C22 toC28 compound such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide,bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide andbis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide]; a mixture thereofand the like. These examples of (D) may be used alone or in combinationof two or more thereof.

Among the above-mentioned examples of (D), from the viewpoint of lightresistance such that the cured product is less apt to turn yellow,preferred are acetophenone compounds and phosphine oxides, furtherpreferred are 1-hydroxycyclohexylphenyl ketone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one,2,4,6-trimethylbenzoyldiphenylphosphine oxide andbis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, andespecially preferred are 1-hydroxycyclohexylphenyl ketone and2,4,6-trimethylbenzoyldiphenylphosphine oxide.

The contents (% by weight) of (A) to (D) in the modeling material arepreferably 50 to 90%, further preferably 55 to 85% of (A) from theviewpoints of enhancement in Tg and brittleness resistance of thephotocured product; preferably 3 to 25%, further preferably 4 to 20% of(B) from the viewpoints of mechanical strength and brittlenessresistance of the photocured product; preferably 5 to 35%, furtherpreferably 8 to 30% of (C) from the viewpoints of toughness and hardnessof the photocured product; and preferably 0.1 to 10%, further preferably0.3 to 8% of (D) from the viewpoints of photocuring rate and mechanicalproperties of the photocured product.

[Other Additive Agents (E)]

Other additive agents (E) may be incorporated into the modeling materialif necessary as long as the effect of the present invention is notimpaired. Examples of (E) include a polymerization inhibitor, asurfactant, a coloring agent, an oxidation inhibitor, a chain transferagent, a filler and the like. Various additive agents may be selectedaccording to the purpose and may be used alone or in combination of twoor more thereof.

In a production method of a photofabrication model by ink-jet threedimensional printing system according to the present invention describedlater, although the forming temperature varies with the ink-jet method,the temperature is about 50 to 90° C. in many instances and it ispreferred to employ a polymerization inhibitor from the viewpoints ofavoidance of the runaway polymerization and enhancement in stability ofthe monomer in the apparatus.

Examples of the polymerization inhibitor include phenol compounds[hydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-p-cresol,2,2-methylene-bis-(4-methyl-6-t-butylphenol),1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane and the like],sulfur compounds [dilauryl thiodipropionate and the like], phosphoruscompounds [triphenyl phosphite and the like], amine compounds[phenothiazine and the like] and the like. The amount of thepolymerization inhibitor used is usually not more than 5%, and ispreferably 0.1 to 3% from the viewpoints of stability and polymerizationrate of the monomer, on the basis of the total weight of (A) to (D).

Examples of the surfactant include an agent with a molecular weight of264 or more and an Mn of 5,000 or less such as a PEG-based nonionicsurfactant [a 1- to 40-mol ethylene oxide (hereinafter, abbreviated asEO) adduct of nonylphenol, a 1- to 40-mol EO adduct of stearic acid andthe like], a polyhydric alcohol-based nonionic surfactant (sorbitanpalmitic acid monoester, sorbitan stearic acid monoester, sorbitanstearic acid triester and the like), a fluorine-containing surfactant (a1- to 50-mol perfluoroalkyl EO adduct, perfluoroalkyl carboxylate,perfluoroalkyl betaine and the like), and a modified silicone oil [apolyether modified silicone oil, a (meth)acrylate modified silicone oiland the like]. The amount of the surfactant used is usually not morethan 3%, and is preferably 0.1 to 2% from the viewpoints of additioneffects and physical properties of the photocured product, on the basisof the total weight of (A) to (D).

Examples of the coloring agent include a pigment and/or a dye. Examplesof the pigment include organic and inorganic pigments and the followingagents can be mentioned as examples. (1) an azo pigment such as aninsoluble monoazo pigment (toluidine red, permanent carmine FB, fastyellow G and the like), an insoluble disazo pigment (disazo yellow AAA,disazo orange PMP and the like), an azo lake (a soluble azo pigment)(lake red C, brilliant carmine 6B and the like), a condensed azo pigmentand a chelate azo pigment; (2) a polycyclic pigment such asphthalocyanine blue, indanthrone blue, quinacridone red and dioxazineviolet; (3) a dye lake such as a basic dye (victoria pure blue BO lakeand the like) and an acid dye (alkali blue toner and the like); and (4)others such as an azine pigment (aniline black and the like), a daylightfluorescent pigment, a nitroso pigment, a nitro pigment and a naturalpigment.

Examples of the inorganic pigment include the following (1) and (2): (1)a metal oxide (iron oxide, chromium oxide, titanium oxide and the like);and (2) carbon black.

The amount of the coloring agent used is usually not more than 2%, andis preferably 0.1 to 1% from the viewpoints of coloration effects andphysical properties of the photocured product, on the basis of the totalweight of (A) to (D).

Examples of the oxidation inhibitor include phenol compounds {monocyclicphenols (2,6-di-t-butyl-p-cresol and the like), bisphenols[2,2′-methylenebis(4-methyl-6-t-butylphenol) and the like], polycyclicphenols[1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene andthe like] and the like}, sulfur compounds (dilauryl3,3′-thiodipropionate and the like), phosphorus compounds (triphenylphosphite and the like) and amine compounds (octylated diphenylamine andthe like). The amount of the oxidation inhibitor used is usually notmore than 3%, and is preferably 0.1 to 2% from the viewpoints ofantioxidant effects and physical properties of the photocured product,on the basis of the total weight of (A) to (D).

Examples of the chain transfer agent include hydrocarbons [a C6 to C24compound such as an aromatic hydrocarbon (toluene, xylene and the like)and an unsaturated aliphatic hydrocarbon (1-butene, 1-nonene and thelike)]; halogenated hydrocarbons (a C1 to C24 compound such asdichloromethane and carbon tetrachloride); alcohols (a C1 to C24compound such as methanol and 1-butanol); thiols (a C1 to C24 compoundsuch as ethylthiol and 1-octylthiol); ketones (a C3 to C24 compound suchas acetone and methyl ethyl ketone); aldehydes (a C2 to C18 compoundsuch as 2-methyl-2-propyl aldehyde and 1-pentyl aldehyde); phenols (a C6to C36 compound such as phenol and m-, p- and o-cresol); quinones (a C6to C24 compound such as hydroquinone); amines (a C3 to C24 compound suchas diethylmethylamine and diphenylamine); and disulfides (a C2 to C24compound such as diethyl disulfide and di-1-octyl disulfide). The amountof the chain transfer agent used is usually not more than 10%, and ispreferably 0.05 to 5% from the viewpoints of polymerizability of themonomer and compatibility of the monomer and the chain transfer agent,on the basis of the total weight of (A) to (D).

Examples of the filler include metal powders (aluminum powder, copperpowder and the like), metal oxides (alumina, silica, talc, mica, clayand the like), metal hydroxides (aluminum hydroxide and the like), metalsalts (calcium carbonate, calcium silicate and the like), fibers[inorganic fibers (carbon fibers, glass fibers, asbestos and the like),organic fibers (cotton, nylon, acrylic, rayon fibers and the like) andthe like], microballoon (glass, shirasu, phenolic resin and the like),carbon (carbon black, graphite, coal powder and the like), metalsulfides (molybdenum disulfide and the like), and organic powders (wooddust and the like). The amount of the filler used is usually not morethan 30%, and is preferably 3 to 20% from the viewpoints of packingeffects, viscosity that allows ink-jet discharge and physical propertiesof the photocured product, on the basis of the total weight of (A) to(D).

The total amount of (E) used is usually not more than 30%, and ispreferably 0.05 to 20% from the viewpoints of addition effects andphysical properties of the photocured product, on the basis of the totalweight of (A) to (D).

[Water-Soluble Component in Modeling Material]

The content of a water-soluble component in the modeling material ispreferably 10% by weight or less, further preferably 5% by weight orless from the viewpoint of preventing the swelling deformation due towater and the deformation due to moisture absorption of the photocuredproduct. It should be noted that in this context, the water-solublecomponent refers to a component with the above defined solubility inwater of 1 (g/100 g of water) or more and a component that exhibits thesolubility among (A) to (D) constituting the modeling material and (E)added if necessary.

[Tg of Photocured Product of Modeling Material]

In the three dimensional printing system employing an ink-jet method,since the photofabrication is carried out usually at 50 to 90° C., theTg of a photocured product of the modeling material is preferably 50 to120° C., further preferably 55 to 110° C., especially preferably 60 to100° C. from the viewpoints of heat resistance of the photocured productand reducing the warpage of the photofabrication model. In this context,the Tg of a photocured product is a value evaluated by the methoddescribed later. The Tg may be adjusted so as to fall in theabove-mentioned range by selecting the kind and content of each of theingredients (A) to (D) constituting the modeling material.

[Water-Swelling Ratio of Photocured Product of Modeling Material]

The water-swelling ratio of the photocured product of the modelingmaterial (% by weight) is preferably not more than 1%, furtherpreferably not more than 0.7%, especially preferably not more than 0.5%from the viewpoint of photofabrication accuracy. In this context, thewater-swelling ratio of the photocured product is a value evaluated bythe method described later. The water-swelling ratio may be adjusted soas to fall in the above-mentioned range by selecting the kind andcontent of each of the ingredients (A) to (D) constituting the modelingmaterial.

[Swelling deformation due to water of photocured product of modelingmaterial]

The swelling deformation due to water of the photocured product of themodeling material (mm) is preferably not more than 2 mm, furtherpreferably not more than 1 mm, especially preferably not more than 0.5mm from the viewpoint of photofabrication accuracy. In this context, theswelling deformation due to water is a value evaluated by the methoddescribed later. The swelling deformation due to water may be adjustedso as to fall in the above-mentioned range by selecting the kind andcontent of each of the ingredients (A) to (D) constituting the modelingmaterial.

The modeling material according to the present invention is used as themodeling material employed for a two-pack photocurable resin compositionincluding a combination of a modeling material for forming aphotofabrication model in ink-jet three dimensional printing system anda supporting material for supporting the shape of the photofabricationmodel on photofabrication. Although known supporting materials may beused as the supporting material combinedly used in the two-packphotocurable resin composition, it is preferred to use the followingsupporting material according to the present invention from theviewpoints of ease of removal after photofabrication due to excellentsolubility in water of the photocured product and excellent workingaccuracy and mechanical properties of the photofabrication model due toincompatibility with the modeling material.

[Supporting Material]

The supporting material according to the present invention contains awater-soluble monofunctional ethylenically unsaturated monomer (F), analkylene oxide adduct containing an oxypropylene group and/or water (G),and a photopolymerization initiator (D).

[Water-Soluble Monofunctional Ethylenically Unsaturated Monomer (F)]

The water-soluble monofunctional ethylenically unsaturated monomer (F)is employed as a constituent ingredient of the supporting material inorder to allow the cured product of the supporting material to dissolverapidly in water after photofabrication.

Although a water-soluble polyfunctional ethylenically unsaturatedmonomer (H) in (F) may be produced as a by-product during the productionprocess of (F), the content thereof is preferably not more than 1%,further preferably not more than 0.5%, especially preferably 0% from theviewpoint of water-solubility of the homopolymer of (F) afterpolymerization.

Examples of (F) include C5 to C15 hydroxyl group-containing(meth)acrylates [hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like]; hydroxylgroup-containing (meth)acrylates with an Mn of 200 to 1,000[polyethylene glycol mono(meth)acrylate, monoalkoxy (C1 to C4)polyethylene glycol mono(meth)acrylate, polypropylene glycolmono(meth)acrylate, monoalkoxy (C1 to C4) polypropylene glycolmono(meth)acrylate, mono(meth)acrylate of PEG-PPG block polymer and thelike]; C3 to C15 (meth)acrylamide derivatives [(meth)acrylamide,N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl(meth)acrylamide, N-butyl (meth)acrylamide, N,N′-dimethyl(meth)acrylamide, N,N′-diethyl (meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-hydroxypropyl (meth)acrylamide, N-hydroxybutyl(meth)acrylamide and the like]; (meth)acryloyl morpholine and the like.These examples may be used alone or in combination of two or morethereof.

Examples of the water-soluble polyfunctional ethylenically unsaturatedmonomer (H) include polyethylene glycol di(meth)acrylate, polypropyleneglycol di(meth)acrylate and di(meth)acrylate of PEG-PPG block polymer.

Among the above-mentioned examples of (F), from the viewpoint ofphotoreactivity, preferred are acrylates and acrylamide derivatives,further preferred are hydroxyethyl acrylate, hydroxypropyl acrylate and4-hydroxybutyl acrylate, acrylamide, acryloyl morpholine, N-methylacrylamide, N-ethyl acrylamide, N-propyl acrylamide, N-butyl acrylamide,N,N′-dimethyl acrylamide, N,N′-diethyl acrylamide, N-hydroxyethyl-,N-hydroxypropyl- and N-hydroxybutyl acrylamide. Moreover, from theviewpoint of low stimulative effect on the skin of the human body,preferred are acryloyl morpholine and N-hydroxyethyl acrylamide.

[Alkylene Oxide Adduct Containing Oxypropylene Group and/or Water (G)]

Examples of (G) include an alkylene oxide adduct containing anoxypropylene group and an adduct obtained by subjecting an activehydrogen compound to an addition reaction of at least propylene oxidealone or of propylene oxide and any other alkylene oxide. Among these,preferred is a homoadduct of propylene oxide (polyoxypropylene glycol).Examples of the active hydrogen compound include mono- to tetrahydricalcohols and amine compounds, and among these, preferred are dihydricalcohols and water.

Examples of (G) include polyoxypropylene glycol which is compatible with(F) before curing and is not compatible with the photocured product of(F) and having a number average molecular weight of 100 to 5,000 and/orwater from the viewpoint of allowing the supporting strength andsolubility in water of the cured product of the supporting material tobe compatible. The number average molecular weight of polyoxypropyleneglycol is preferably 200 to 3,000, more preferably 400 to 2,000.

On the other hand, from the viewpoint of prevention of compatibilizationor prevention of intermixing of the modeling material and the supportingmaterial before curing, preferred is water. In the case where (G) iswater, since the modeling material and the supporting material beforecuring do not compatibilize or intermix with each other, a problem ofdecreased various physical properties at an intermixed part of each ofthe modeling material and the supporting material and a problem ofswelling deformation, resulting from the problem of compatibilizationand intermixing of the modeling material and the supporting materialbefore curing, may be completely solved.

[Photopolymerization Initiator (D)]

As a photopolymerization initiator used for the supporting material, onethat is the same as the photopolymerization initiator (D) for themodeling material is basically used. In the case where (G) is water, awater-soluble photopolymerization initiator is used. Among the examplesof (D), as the water-soluble photopolymerization initiator,1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-prop air 1-one and the like canbe mentioned and it is not particularly limited as long as it iswater-soluble.

The contents (% by weight) of (F), (G) and (D) in the supportingmaterial are preferably 3 to 45%, further preferably 3 to 43%,especially preferably 4 to 40% of (F) from the viewpoint of allowing thephotocured product of the supporting material to remain solid and toexert the supporting strength and the viewpoint of solubility in waterof the photocured product; preferably 50 to 95%, further preferably 53to 93%, especially preferably 55 to 90% of (G) from the viewpoints ofsolubility in water of the photocured product and supporting strength;and preferably 0.1 to 10%, further preferably 0.3 to 8%, especiallypreferably 0.5 to 6% of (D) from the viewpoints of photocuringproperties of the supporting material and solubility in water of thephotocured product.

[Other Additive Agents (E)]

Other additive agents (E) may be incorporated into the supportingmaterial if necessary as long as the effect of the present invention isnot impaired. Those that are the same as the other additive agents (E)used for the modeling material may be used for the supporting material.Examples of (E) include a polymerization inhibitor, a coloring agent, anoxidation inhibitor, a chain transfer agent, a filler and the like.Various additive agents may be selected according to the purpose and maybe used alone or in combination of two or more thereof. Each of theamounts of (E) used (%) based on the total weight of (F), (G) and (D) isthe same as each of the amounts of (E) used (%) based on the totalweight of (A) to (D) in the modeling material. Moreover, the totalamount of (E) used (%) based on the total weight of (F), (G) and (D) isalso the same as the total amount of (E) used (%) based on the totalweight of (A) to (D).

[Solubility in Water of Cured Product of Supporting Material]

The solubility in water of the cured product of the supporting materialmay be evaluated on the basis of water dissolution time (the timerequired for the cured product to completely dissolve after theimmersion in water) measured by the method described later. The waterdissolution time is usually not more than 24 hours, and is preferably0.1 to 20 hours, further preferably 0.1 to 12 hours from the viewpointsof supporting strength and working accuracy. The water dissolution timemay be adjusted so as to fall in the above-mentioned range by selecting,with regard to the ingredients (F), (G) and (D) constituting thesupporting material, the kind and amount thereof used.

[Supporting Strength of Cured Product of Supporting Material]

The supporting strength in the present invention means the ability forthe cured product of the supporting material to support the curedproduct of the modeling material and may be represented by the durometerhardness (unit: HDA) of the cured product of the supporting materialmeasured by the method described later. The supporting strength ispreferably 17 to 35, further preferably 20 to 30 from the viewpoints ofworking accuracy of the photofabrication model and solubility in waterof the cured product of the supporting material. The supporting strengthmay be adjusted so as to fall in the above-mentioned range by selecting,with regard to the ingredients (F), (G) and (D) constituting thesupporting material, the kind and amount thereof used.

The supporting material according to the present invention is used asthe supporting material employed for a two-pack photocurable resincomposition including a combination of a modeling material for forming aphotofabrication model in ink-jet three dimensional printing system anda supporting material for supporting the shape of the photofabricationmodel on photofabrication. Although known modeling materials may be usedas the modeling material combinedly used in the two-pack photocurableresin composition, it is preferred to use the above-mentioned modelingmaterial according to the present invention from the viewpoints ofsmallness of the swelling deformation due to water or moistureabsorption on photocuring and after curing and excellent workingaccuracy and mechanical properties of the photofabrication model due toincompatibility with the supporting material.

[Production Method of Photofabrication Model]

The photofabrication model according to the present invention is usuallyproduced by the following procedure with a photofabrication apparatusdescribed later.

(1) Production of Two-Pack Photocurable Resin Composition

A two-pack photocurable resin composition employing a modeling materialaccording to the present invention and a supporting material accordingto the present invention will be described.

(1-1) Production of Modeling Material

The curable resin ingredients (A) to (D) for a modeling material andother additive agents (E) added as needed are uniformly mixed using amixing and stirring device or the like to produce a resin compositionfor a modeling material.

(1-2) Production of Supporting Material

The constituent ingredients (F), (G) and (D) for a supporting materialand other additive agents (E) added as needed are uniformly mixed usinga mixing and stirring device or the like to produce a resin compositionfor a supporting material.

(2) Production of Photofabrication Model with Three-Dimensional ModelingSystem

FIG. 1 is a schematic view of a three-dimensional modeling systememploying an ink-jet method. As shown in FIG. 1, the system is composedof a personal computer or the like 1 and a three-dimensional modelingapparatus 2 connected to the personal computer or the like 1. Thepersonal computer or the like 1 accepts input of three-dimensional CADdata for an object to be formed, converts the CAD data entered into to,for example, STL data as three-dimensional modeling data, and further,from the three-dimensional STL data, creates data of each layer obtainedby slicing the object in the z-direction.

Specifically, in addition to data for a modeling material correspondingto a work to be formed, data for a supporting material for supportingthe modeling material on forming are also created. Generally, in thecase where, for example, in the z-direction, the width of the modelingmaterial located at an upper part thereof is larger than the width ofthe modeling material located at a lower part thereof, namely, the workhas a so-called overhang part, the system is designed so that byarranging a supporting material around the lower part in the x- andy-directions using software installed in the personal computer or thelike 1, the supporting material is automatically provided and theoverhang part is supported from the lower part.

Furthermore, the personal computer or the like 1 has a function ofpositioning and determining the posture in the x-, y- and z-directionsof three-dimensional data for modeling within a modeling space possessedby the three-dimensional modeling apparatus 2, while using the STL data.More specifically, it is made possible to display, on a display screenof the personal computer or the like 1, a virtual three-dimensionalspace that three-dimensionally represents the modeling space above themodeling table possessed by the three-dimensional modeling apparatus 2and to display three-dimensional STL data of the object to be formed atthe default location of the space, and by using a pointing device suchas a mouse and a cursor on the display screen, to determine the desiredposition and posture within the modeling space possessed by thethree-dimensional modeling apparatus 2 using the three-dimensional STLdata of the object to be formed.

The three-dimensional modeling apparatus 2 carries out the formation ofeach layer by receiving data of each layer obtained by slicing theobject in the z-direction described above in a lump or in each layeraligned from the personal computer or the like 1, allowingtwo-dimensional printer heads described later possessed by thethree-dimensional modeling apparatus 2 to scan in a main scanningdirection (x-direction) and a vertical scanning direction (y-direction)on the basis of the data of each layer, and discharging a modelingmaterial and a supporting material from a printer head for modelingmaterial discharge and a printer head for supporting material discharge,respectively.

FIG. 2 and FIG. 3 are schematic views showing the configuration of thethree-dimensional modeling apparatus 2, and FIG. 2 is a side view andFIG. 3 is a plan view. As shown in the drawings, the three-dimensionalmodeling apparatus 2 has a modeling table 21 which is movable in thez-direction, a printer head 22 for modeling material for discharging amodeling material onto the modeling table, a printer head 23 forsupporting material for discharging a supporting material onto themodeling table, a roller 24 for removing the excess modeling materialand supporting material in order to smooth the top surface of the layerformed on the modeling table 21 after discharged from the printer heads22 and 23, and a UV light source 25 for photocuring at least themodeling material applied.

The above-described printer heads 22 and 23, the roller 24 forsmoothing, and the UV light source 25 are mounted in place on a printerhead module 26 and integrally driven in a main scanning direction(x-direction) and a vertical scanning direction (y-direction) above themodeling table 21 by a driving means which is not depicted.

FIG. 4 is a schematic view of one of printer heads 22 and 23, viewedfrom the lower part. As shown in FIG. 4, each of the printer heads 22and 23 has plural orifices for discharging a modeling material or asupporting material disposed at predetermined intervals in the verticalscanning direction (y-direction) on the surface opposite to the modelingtable.

In FIG. 2, when the module moves in a main scanning direction (adirection of forward movement) in which the module moves from the leftside to the right side and a modeling material and a supporting materialare discharged at least from the printer heads 22 and 23 onto themodeling table, the roller 24 works in the case where the module movesin a direction of backward movement in which the module moves from theright end of the main scanning direction to the left. On that occasion,the rotation direction of the roller is the direction of the arrow shownin the drawing and thus the roller revolves clockwise. In other words,it is preferred that the roller 24 be controlled so as to revolve in thesame direction as the direction in which the printer head module 26scans when the roller 24 works.

The UV light source 25 extends along the vertical scanning direction andit is desirable that the length thereof be at least as long as thelength ranging over all the orifices disposed on each printer head.Moreover, as the UV light source 25, it is preferred to employ a UV lampcommonly frequently used for curing the photocurable resin or a LED.Moreover, the modeling table 21 is moved, by a driving means which isnot depicted, downward (in the z-direction) by the thickness of eachlayer prior to the formation of the following layer every time eachlayer is formed on the basis of each slice data corresponding to eachlayer.

FIG. 5 is a schematic view of a materials supply system in which amodeling material and a supporting material are supplied to both printerheads 22 and 23 respectively. To each of the printer heads 22 and 23,cartridges 27 and 28 containing a modeling material and a supportingmaterial are connected respectively and into each of the intermediateconnection routes, feed pumps 29 and 30 are inserted respectively. Eachof the cartridges 27 and 28 is interchangeable in the case where themodeling material or the supporting material as the contents thereof hasbeen consumed.

Next, a three-dimensional modeling method using the above-mentionedthree-dimensional modeling system employing an ink-jet method will bedescribed. When CAD data for three-dimensional modeling are entered inthe personal computer or the like 1, the data are converted to STL dataand after the posture of three-dimensional data (model) within themodeling space possessed by the three-dimensional modeling apparatus 2is determined on the display screen described above, each slice data inthe z-direction is transferred to the three-dimensional modelingapparatus 2 from the personal computer or the like 1. Thethree-dimensional modeling apparatus 2 stacks layers, each of whichcorresponds to each slice data, on top of each other by allowing theprinter head module 26 to move back and forth in the main scanningdirection and, while allowed to move back and forth, controlling thedischarge of the modeling material and the supporting material from eachof the printer heads 22 and 23 onto appropriate locations on the basisof each slice data received. For each layer, at least the modelingmaterial is discharged from the printer head 22 onto an appropriatelocation and, if necessary, the supporting material is also dischargedfrom the printer head 23 onto an appropriate location to form eachlayer.

Furthermore, for example, when a modeling material and a supportingmaterial are discharged from each of the printer heads 22 and 23 duringthe course of allowing the printer head module 26 to move in thedirection from left to right in FIG. 2 (the direction of forwardmovement), the roller 24 continues to revolve in the above-describedrotation direction during the course of allowing the module to move inthe direction of backward movement (the direction from right to left inFIG. 2), while being in contact with the surfaces of the modelingmaterial and the supporting material, in order to smooth the surfacecomposed of the modeling material and the supporting material that havealready been applied on the modeling table 21 and to remove the excessmaterial. Then, by irradiating the surface smoothed with the roller 24with ultraviolet rays from the UV light source 25 mounted on the printerhead module 26, the layer located on the top surface of the objectformed on the modeling table 21 is allowed to be cured. In thisconnection, it goes without saying that each layer is formed from atleast the modeling material and formed by being added with thesupporting material if necessary. Thus, the formation of each layer iscarried out by discharging a modeling material and a supporting materialfrom each of the printer heads 22 and 23, forming a layer located on thetop surface of the object on the modeling table 21, smoothing thesurface of the layer with the roller 24, and curing the layer byirradiating the layer located on the top surface of the object on themodeling table 21 with ultraviolet rays. By repeating these steps, athree-dimensional model is formed.

FIG. 6 is a schematic view showing the halfway state of athree-dimensional model prepared while operating a three-dimensionalmodeling apparatus 2. The portion represented by M shown in the drawingis the portion of stacked layers formed from the modeling material andthe portion represented by S is the portion of stacked layers formedfrom the supporting material. As described above, the model is allowedto form so that the supporting materials are deposited on the portionsrepresented by S in order to support the curved parts at the left andright of the modeling material shown in the drawing since the modelingmaterial of the portion represented by M has an approximately S-shapeformed from the lower part to the upper part in the z-direction.

FIG. 7(A) is a schematic view showing a model accompanied by supportingmaterials after the completion of forming like this, and FIG. 7(B) is aschematic view showing a model obtained by removing supporting materialsfrom the model accompanied by supporting materials after the completionof forming. As shown in FIG. 7(A), when the formation of thethree-dimensional model using the three-dimensional modeling apparatus 2is completed, the model and the supporting materials for supporting themodeling material on forming are still integrally formed. As such, sincethe supporting material is composed of the water-soluble material, forexample, by immersing it in water, it is made possible to obtain a modelcomposed only of such a modeling material shown in FIG. 7(B).

EXAMPLES

Hereinafter, the present invention will be described in more detail byreference to examples, but the present invention is not limited thereto.It should be noted that part and % refer to part by weight and % byweight respectively unless otherwise stated.

Production Example 1

In a reaction vessel were placed 100 parts of a caprolactone adduct of2-hydroxyethyl acrylate [trade name “Placcel FA-4 D”, available fromDaicel Chemical Industries, Ltd, number of moles added: 4], 64 parts ofa nurate of IPDI [trade name “VESTANAT T1890”, available from DegussaJapan Co., Ltd.], and 0.03 parts of a urethanization catalyst [bismuthtris(2-ethylhexanoate) (a 50% 2-ethylhexanoic acid solution); the sameholds true for description below], and allowed to undergo a reaction for12 hours at 80° C. to give urethane acrylate (C-1). The Mn of (C-1) was1,730.

Production Example 2

In a reaction vessel were placed 100 parts of polytetramethylene glycol[trade name “PTMG-1000”, available from Mitsubishi Chemical Corporation,Mn 1,000], 33.3 parts of IPDI and 0.05 parts of a urethanizationcatalyst, and allowed to undergo a reaction for 4 hours at 80° C., afterwhich 11.6 parts of 2-hydroxyethyl acrylate (NCO/OH equivalentratio=1/1) was added and allowed to undergo a reaction for 8 hours at80° C. to give urethane acrylate (C-2). The Mn of (C-2) was 1,606.

Production Example 3

In a reaction vessel equipped with a stirrer were placed 28.59 parts ofTDI, 0.021 parts of 2,6-di-tert-butyl-p-cresol, 0.072 parts ofdibutyltin dilaurate and 0.007 parts of phenothiazine and cooled withice until the liquid temperature became 10° C. or lower with stirring.To the mixture, 26450 parts of oxypropylene glycol with a number-averagemolecular weight of 1000 was added and allowed to undergo a reactionwith stirring for 2 hours while controlling the liquid temperature so asto become 35° C. or lower. Next, to the mixture, 9.70 parts of2-hydroxypropyl acrylate was added dropwise and 24.74 parts ofhydroxyethyl acrylate was further added dropwise. The stirring wascontinued for 3 hours at a liquid temperature of 70 to 75° C. and thereaction was discontinued at the point of time at which the residualisocyanate group concentration became 0.1% or less to give urethaneacrylate “UA-1”. (the method of [Synthesis Example 1: Synthesis ofUrethane acrylate (B)] described in Japanese Patent Laid-Open No.2010-155926)

Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-5

By uniformly mixing raw materials so as to allow the blendingcomposition (parts) to be the one listed in Table 1, each modelingmaterial of examples and comparative examples was obtained. Eachmodeling material was evaluated in <Evaluation item 1> described later.The results are shown in Table 1. In this context, as the modelingmaterials in Comparative Example 1-1; Comparative Examples 1-2 and 1-3;and Comparative Example 1-4, the modeling materials described in theabove-mentioned Patent Document 1 (Japanese Patent Laid-Open No.1-204915); Patent Document 13 (Japanese Patent Laid-Open No.2010-155926); and Patent Document 10 (EP Patent No. 1274551B1) wereemployed, respectively.

Examples 2-1 to 2-13 and Comparative Examples 2-1 to 2-6

By uniformly mixing raw materials so as to allow the blendingcomposition (parts) to be the one listed in Table 2, each supportingmaterial of examples and comparative examples was obtained. Eachsupporting material was evaluated in <Evaluation item 2> describedlater. The results are shown in Table 2. In this context, as thesupporting materials in Comparative Examples 2-1 and 2-2; andComparative Examples 2-3 and 2-4, the supporting materials described inthe above-mentioned Patent Document 10 (EP Patent No. 1274551B1); andPatent Document 12 (Japanese Patent Laid-Open No. 2010-155889) wereemployed, respectively.

Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-3

By using a modeling material and a supporting material in combination asshown in Table 3, the relations of modeling material/supporting materialwere evaluated in <Evaluation item 3> described later. The results areshown in Table 3. In this context, for the modeling material/supportingmaterial combination in comparative examples, as the combinations inComparative Examples 3-1 and 3-2 and Comparative Example 3-3, thosedescribed in the above-mentioned Patent Document 12 and 13 and PatentDocument 10 were employed, respectively.

TABLE 1 sp Water Examples Comparative Examples Value solubility 1-1 1-21-3 1-4 1-5 1-6 1-7 1-1 1-2 1-3 1-4 1-5 Blending A A-1 9.62 70 75 60 6080 50 20 40 composition A-2 12.72 ◯ 10 40 55 50 (parts by weight) A-311.93 ◯ A-4 10.12 A-5 9.32 18 10 A-6 8.66 62 35 B B-1 9.92 10 5 20 10 1010 15 25 B-2 11.39 60 35 40 B-3 9.72 50 B-4 9.56 C C1 10.7 20 20 20 3010 C2 9.68 30 10 5 10 10 UA-1 8.8 C-3 10.7 10 D D-1 11.1 5 5 5 3 1 3 3 33 D-2 12.24 5 5 3 4 D-3 10.52 E E-1 0.1 E-2 0.1 E-3 0.05 sp Value 9.99.9 9.9 9.7 9.7 10.3 9.0 9.4 10.7 10.9 12.0 12.0 Evaluation item 1 Tg 7771 90 77 88 73 80 67 65 61 55 60 Swelling ratio 0.1 0.1 0.1 0.1 0.1 0.50.1 2.1 3.8 1.9 3.3 2.3 Swelling deformation 0.1 0.1 0.1 0.2 0.1 0.2 0.11.1 1.0 1.5 2.4 2.3 caused by immersion in water (mm) Strength ontearing apart 40 30 55 35 40 45 30 14 19 19 12 14 Breaking energy 4.43.5 3.0 3.0 3.5 5.0 3 1.2 1.8 1.3 1.1 1.6 (brittleness) Deformationcaused by 0.1 0.1 0.1 0.1 0.1 0.5 0.1 2.9 2.8 2.1 3.3 2.9 moistureabsorption (40° C. × 90% RH, 24 h) Deformation during storage 0.1 0.10.1 0.1 0.2 0.5 0.1 2.1 2.5 2.2 3.5 3.0 (40° C. × 10% RH, 24 h)

TABLE 2 Examples 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-8 2-9 2-10 Blending FF-1 20 30 40 10 5 40 composition F-2 20 30 40 10 5 (parts by weight) F-3G G-1 40 70 90 95 40 70 90 95 G-2 40 60 40 60 G-3 60 G-4 G-5 G′-1 G′-2 DD-1 3 5 3 3 5 3 D-2 3 3 3 3 D-3 D-4 5 E E-4 E-5 0.1 E-6 0.1 0.1 H H-1H-2 Evaluation Dissolution time (h) 2 3 5 1 0.5 8 1.5 2.5 4 0.8 0.4 item2 Ease of removal of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ supporting materialSupporting strength ⊙ ⊙ ⊙ ◯ ◯ ◯ ⊙ ⊙ ⊙ ◯ ◯ Examples Comparative Examples2-11 2-12 2-13 2-1 2-2 2-3 2-4 2-5 2-6 Blending F F-1 100  36.9 20 20composition F-2 40 40 (parts by weight) F-3 40 40 G G-1 60 G-2 G-3 G-460 G-5 60 G′-1 50.4 80 G′-2 60 60 80 D D-1 3 3 D-2 5 5 5 5 D-3 5 5 5 D-4E E-4   0.5 0.5 E-5 E-6 H H-1 40 40 H-2 12.3 Evaluation Dissolution time(h) 1 2.5 3 Swollen but 48< 24 1 1 item 2 insoluble Ease of removal of ◯◯ ◯ X X X Δ ◯ ◯ supporting material Supporting strength ◯ ◯ ◯ ◯ ◯ ⊙ ◯ XX

TABLE 3 Examples Comparative Examples Modeling material 1-1 1-6 1-2 1-21-4 Evaluation sp Value 9.87 10.3 10.9 10.9 10.4 item 3 Supportingmaterial Example Example Example Example Comparative ComparativeComparative 2-1 2-6 2-1 2-6 Example 2-3 Example 2-4 Example 2-1 Ease ofseparation of modeling Δ ◯ Δ ◯ X X X material and supporting materialState of intermixed part of ◯-Δ ◯ ◯-Δ ◯ X X X modeling material andsupporting material (after immersion in water) Working accuracy ofboundary ◯-Δ ◯ ◯-Δ ◯ X X X between modeling material and supportingmaterial

In this connection, the contents represented by symbols in Tables 1 and2 are as follows. A-1: isobornyl acrylate [trade name “LIGHT ACRYLATEIBXA”, available from Kyoeisha Chemical Co., LTD., average number offunctional groups: 1] A-2: acryloyl morpholine [trade name “ACMO”,available from KOHJIN Holdings Co., LTD., average number of functionalgroups: 1] A-3: 2-hydroxy-3-phenoxypropyl acrylate [trade name “EPDXYESTER M-600A”, available from Kyoeisha Chemical Co., LTD., averagenumber of functional groups: 1] A-4: phenoxyethyl acrylate [trade name“SR-339”, available from Sartomer Company, Inc., average number offunctional groups: 1] A-5: 1-adamantyl acrylate [trade name “1-AdA”,available from Osaka Organic Chemical Industry Ltd., average number offunctional groups: 1] A-6: stearyl acrylate [trade name “STA”, availablefrom Osaka Organic Chemical Industry Ltd., average number of functionalgroups: 1]

B-1: dicyclopentanedimethylol diacrylate [trade name “LIGHT ACRYLATEDCP-A”, available from Kyoeisha Chemical Co., LTD., average number offunctional groups: 2] B-2: an acrylic acid adduct of 2 mol PO modifiedbisphenol A adduct diglycidyl ether [trade name “EPDXY ESTER 3002A”,available from Kyoeisha Chemical Co., LTD., average number of functionalgroups: 2] B-3: trimethylolpropane triacrylate [trade name “SR-351”,available from Sartomer Company, Inc., average number of functionalgroups: 3] B-4: 1,6-hexanediol diacrylate [trade name “LIGHT ACRYLATE1,6HX-A”, available from Kyoeisha Chemical Co., LTD., average number offunctional groups: 2]

C-3: urethane acrylate oligomer [trade name “Photomer 6010”, availablefrom Cognis Japan Ltd., average number of functional groups: 2] D-1:1,3,5-trimethylbenzoyldiphenyl phosphine oxide [trade name “LucirinTPO”, available from BASF Japan Ltd.] D-2: 1-hydroxycyclohexylphenylketone [trade name “IRGACURE 184”, available from Ciba SpecialtyChemicals Inc.] D-3:

2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one [trade name“IRGACURE “907”, available from Ciba Specialty Chemicals Inc.] D-4:1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propan-1-one [trade name“IRGACURE “2959”, available from Ciba Specialty Chemicals Inc.]

E-1: polyether modified polydimethylsiloxane [trade name “BYK 307”,available from BYK Japan KK] E-2: hydroquinone monomethyl ether[available from Wako Pure Chemical Industries, Ltd.] E-3: carbon black[trade name “MHI Black #220”, available from Mikuni Color LTD.]

F-1: N-hydroxyethyl acrylamide [trade name “HEAA”, available from KOHJINHoldings Co., LTD., average number of functional groups: 1] F-2:acryloyl morpholine [trade name “ACMO”, available from KOHJIN HoldingsCo., LTD., average number of functional groups: 1] F-3: polyethyleneglycol monoacrylate (Mn: approximately 336) [trade name “Bisomer PEA6”,available from Cognis Japan Ltd., average number of functional groups:1] G-1: PPG (Mn: approximately 400) [trade name “SANNIX PP-400”,available from Sanyo Chemical Industries, Ltd.] G-2: PPG (Mn:approximately 1000) [trade name “SANNIX PP-1000”, available from SanyoChemical Industries, Ltd.] G-3: water G-4: polyoxyethylenepolyoxypropylene glycol (Mn: approximately 2000) [trade name “NEWPOLPE-61”, available from Sanyo Chemical Industries, Ltd.] G-5:polyoxypropylene glyceryl ether (Mn: approximately 1500) [trade name“SANNIX GP-1500”, available from Sanyo Chemical Industries, Ltd.] G′-1:propylene glycol [available from Wako Pure Chemical Industries, Ltd.]G′-2: PEG (Mn: approximately 400) [trade name “PEG-400”, available fromSanyo Chemical Industries, Ltd.]

E-4: 2,4-diphenyl-4-methyl-pentene [available from Wako Pure ChemicalIndustries, Ltd.] E-5: diphosphorus acid [available from Wako PureChemical Industries, Ltd.] E-6: phenothiazine [available from Wako PureChemical Industries, Ltd.]

H-1: polyethylene glycol diacrylate (Mn: approximately 600) [trade name“SR-610”, available from Sartomer Company, Inc., average number offunctional groups: 2] H-2: polyethylene glycol diacrylate (Mn: 1000)[trade name “SR-740A”, available from Sartomer Company, Inc., averagenumber of functional groups: 3]

[1] Evaluation Method of Modeling Material

A 10-cm by 10-cm square area was separated by means of spacers of 1 mmin thickness arranged as four sides on the top surface of a glass plate[trade name “GLASS PLATE”, available from AS ONE CO., LTD., 200-mm by200-mm by 5 mm thickness]. Into the square area, each of resincompositions (modeling materials) shown in Table 1 was poured, afterwhich another glass plate was overlapped. After irradiated withultraviolet rays of 300 mJ/cm² with an ultraviolet irradiation device[model number “ECS301G1”, available from EYE GRAPHICS CO., LTD., thesame holds true for description below.], the cured product was removedfrom the glass plate and cut into pieces of 5 mm width by 50 mm lengthby a cutter to obtain test specimens of the molded product. Theperformance evaluation of the test specimen was carried out by thefollowing method. The results are shown by the average of valuesobtained from five test specimens.

<Evaluation Item 1>(1) Glass Transition Point (Tg) (° C.)

The glass transition point was measured at 10 Hz by a DMA method using astretch mode with a dynamic viscoelasticity measuring apparatus (DMA)[model number “Rheogel-E4000”, available from UBM CO., LTD.].

(2) Water-Swelling Ratio (%)

The water-swelling ratio was measured in accordance with the waterabsorption measuring method of ASTM D570. The swelling ratio (%) wasdetermined by the following equation. Here, ion-exchanged water wasemployed as the water and the measurement was carried out at 25° C.Water-swelling ratio (%)=100×(weight after immersion in water−weightbefore immersion in water)/(weight before immersion in water)(3) Swelling Deformation Caused by Immersion in Water (Mm)

A test specimen was immersed in water in the same manner as in theabove-mentioned (2). The test specimen was horizontally laid on a tableimmediately after removed from the water, and the maximum distance (mm)between the end of the test specimen with a warpage and the surface ofthe table was measured and defined as the swelling deformation caused byimmersion in water.

(4) Strength on Tearing Apart (N/Mm²)

The tensile strength on tearing apart was measured in accordance withJIS K7113 by stretching a test specimen at a test rate of 50 mm/minutewith Autograph [available from Shimadzu Corp.] and defined as thestrength on tearing apart.

(5) Breaking Energy (Brittleness) (J)

The energy applied until tearing apart on measurement of theabove-mentioned (4) was determined from the area of the stress-straincurve until tearing apart and defined as the breaking energy. The largerthe breaking energy is, the more excellent in toughness the testspecimen is, and the smaller the breaking energy is, the brittler thetest specimen is.

(6) Deformation Caused by Moisture Absorption (Mm)

One end in the direction of the length of a test specimen was fixed to achuck (distance for a grasp: 5 mm) and allowed to settle for 24 hours ina thermohygrostat (40° C., 90% RH) in a state of being fixedhorizontally, after which the distance between the other end of the testspecimen, which is at opposite side of the fixed end and allowed to bedeformed to sag because of gravity, and the initial horizontal plane wasmeasured and defined as the deformation caused by moisture absorption(mm).

(7) Deformation During Storage (mm)

A test specimen was allowed to settle for 24 hours in a thermohygrostat(40° C., 10% RH) in a state of being fixed horizontally in the samemanner as in the above-mentioned (6), after which the distance betweenthe other end of the test specimen, which is at opposite side of thefixed end and allowed to be deformed to sag because of gravity, and theinitial horizontal plane was measured and defined as the deformationduring storage (mm).

[2] Evaluation Method of Supporting Material

<Evaluation Item 2>(1) Water Dissolution Time (h)

On the upper surface of a microscope slide [trade name “MICRO SLIDEGLASS S1225”, available from Matsunami Glass Ind., Ltd., 76-mm by 26-mmby 1.2 to 1.5 mm thickness, the same holds true for description below],1 g of each of resin compositions (supporting materials) shown in Table2 was placed and irradiated with ultraviolet rays of 300 mJ/cm² with anultraviolet irradiation device to obtain a cured product. The waterdissolution time of the cured product was measured by the followingmethod (evaluation of solubility in water). In a 100-ml beaker wasplaced 100 ml of ion-exchanged water and in this was immersed the curedproduct. The cured product was visually observed every 1 hour and thetime required for the cured product to completely dissolve after thestart of immersion was defined as the water dissolution time.

(2) Ease of Removal of Supporting Material

A silicone rubber stopper [trade name “Silicone rubber stopper No. 1”,available from TERAOKA CORPORATION, 16 mm in upper diameter, 12 mm inlower diameter, 19 mm in height] was subjected to a drilling operationto contain a hole of 4 mm in diameter that pierces the central partlengthwise, and placed on a microscope slide so that the hole facedupward. A supporting material was poured into the hole and the hole wasfilled with the material. The supporting material was irradiated withultraviolet rays of 1000 mJ/cm² with an ultraviolet irradiation deviceto obtain a cured product. Next, in 100 ml of ion-exchanged watercontained in a beaker, the cured product accompanied by the siliconerubber stopper was immersed. After 24 hours, the silicone rubber stopperwas removed and the ease of removal of supporting material was evaluatedaccording to the following criteria.

<Evaluation criteria>◯: The ease of removal of supporting material isgood. (The hole is completely pierced.) Δ: The ease of removal ofsupporting material is insufficient. (There is a portion where the holeis not pierced.) x: The ease of removal of supporting material is poor.(The hole is clogged with the cured product that has swelled.)(3) Supporting Strength (HDA Hardness)

The supporting strength means the ability for the cured product of thesupporting material to support the cured product of the modelingmaterial and was evaluated on the basis of the type A durometer hardnessin accordance with JIS K7215. The specimen for evaluation was preparedin the following manner and the hardness measurement was carried out byusing the specimen of approximately 5 mm in thickness. A 3-cm by 3-cmsquare area was separated by means of spacers of 5 mm in thicknessarranged as four sides on the top surface of a glass plate [trade name“GLASS PLATE”, available from AS ONE CO., LTD., 200-mm by 200-mm by 5 mmthickness]. Into the square area, a resin composition shown in Table 1was poured, after which another glass plate was overlapped so as to keepthe air out (in the case where the air was admitted, the glass plate wasinclined to exclude the air). After irradiated with ultraviolet rays of1,000 mJ/cm² with an ultraviolet irradiation device, the cured productwas removed from the glass plate to obtain the molded product.

<Evaluation criteria>⊙: The supporting strength is sufficient. (HDA of25 to less than 36) ◯: The supporting strength is adequate. (HDA of 17to less than 25) Δ: The supporting strength is insufficient. (HDA of 10to less than 17) x: The supporting strength is poor. (HDA of less than10) When the HDA is not less than 36, the ease of removal of supportingmaterial deteriorates.[3] Evaluation Method of Relations of Modeling Material/SupportingMaterial<Evaluation Item 3>(1) Ease of Separation of ModelingMaterial/Supporting Material

In a 10-ml graduated cylinder [trade name “TPX graduated cylinder”,available from TERAOKA CORPORATION], 3 g of a resin composition as thesupporting material shown in Table 2 (one kind among Examples 2-1 to2-13 and Comparative Examples 2-1 to 2-6) was placed. On the supportingmaterial, 3 g of a resin composition as the modeling material shown inTable 1 (one kind among Examples 1-1 to 1-7 and Comparative Examples 1-1to 1-5) was gently placed so as not to intermix with the supportingmaterial. The whole graduated cylinder was wrapped with aluminum foil soas to keep the light out and the visual appearance after standing for 24hours was observed. The ease of separation of the modeling material andthe supporting material was evaluated according to the followingcriteria.

<Evaluation criteria>⊙: The ease of separation is good. (The modelingmaterial and the supporting material separate completely at theinterface therebetween.) ◯: The ease of separation is adequate. (Themodeling material and the supporting material separate substantially atthe interface therebetween.) Δ: The ease of separation is insufficient.(The modeling material and the supporting material separate but theinterface is in the compatibilized state and is milky.) x: The ease ofseparation is poor. (The modeling material and the supporting materialare totally in the compatibilized state and is milky.)(2) State of Contact Part of Modeling Material/Supporting Material(after Immersion in Water)

On the upper surface of a microscope slide, a modeling material and asupporting material were combinedly placed in portions of 1 g each sothat resin compositions were adjacent to and brought into contact witheach other, and irradiated with ultraviolet rays of 300 mJ/cm² with anultraviolet irradiation device to obtain a cured product. Next, in 100ml of ion-exchanged water contained in a beaker, the cured productaccompanied by the microscope slide was immersed. After 24 hours, thecured product was removed and the state of the cured product surface ofthe modeling material with which the supporting material had beenbrought into contact was evaluated according to the following criteria.

<Evaluation criteria>◯: The surface is the same condition as that of acured product obtained by curing a modeling material by itself. (Thecured product of the supporting material does not remain on the surfacewith which the supporting material has been brought into contact.) Δ:The surface is somewhat sticky. (Small amounts of the cured product ofthe supporting material remain on the surface with which the supportingmaterial has been brought into contact.) x: The surface is swollen in agel-like state. (Large amounts of the cured product of the supportingmaterial remain on the surface with which the supporting material hasbeen brought into contact. The modeling material and the supportingmaterial intermix.)(3) Working Accuracy of Boundary of Modeling Material/SupportingMaterial

A cured product was prepared in the same manner as in theabove-mentioned <Evaluation item 3>(2) except that shortly beforeirradiation with an ultraviolet irradiation device, a needle (1.0 mm indiameter) was stuck perpendicularly into the modeling material and thetip of the needle was allowed to reach the glass surface, after whichkeeping the state of the needle unchanged, the needle was horizontallytransferred to the side of the supporting material to prepare a part ofthe modeling material extending thinly into the supporting material. Theirradiation of ultraviolet rays was immediately carried out under suchconditions and the resulting cured product was immersed in ion-exchangedwater in the same manner as in the above-mentioned <Evaluation item3>(2). After 24 hours, the cured product was removed and the state ofthe boundary between the modeling material and the supporting materialwas evaluated according to the following criteria.

<Evaluation criteria>◯: The working accuracy of the boundary is good.(Almost all the thinly extended part of the modeling material is curedand still remains.) Δ: The working accuracy of the boundary is somewhatpoor. [Only the root part of the thinly extended part of the modelingmaterial (area of cross section of approximately 1 mm²) is cured andremains.] x: The working accuracy is poor. (The thinly extended part ofthe modeling material disappears and the extended part cannot bedefined.)

The results shown in Table 1 reveal that the formed product obtained bycuring the resin compositions (Examples 1-1 to 1-7) as the modelingmaterial according to the present invention is superior to the formedproduct obtained by curing the resin compositions (Comparative Examples1-1 to 1-5) as the comparative modeling material because there is littleswelling deformation due to water or little deformation on drying and itis made possible to inhibit the deformation of the photofabricationproduct due to moisture absorption after curing of the modeling materialand the like, as well as to enhance the working accuracy of the modelingmaterial on photofabrication. The results shown in Table 2 reveal thatthe cured product obtained by curing the resin compositions (Examples2-1 to 2-13) as the supporting material according to the presentinvention is excellent in allowing solubility in water and supportingstrength to be compatible compared to the cured product obtained bycuring the resin compositions (Comparative Examples 2-1 to 2-6) as thecomparative supporting material. Moreover, the results shown in Table 3reveal that the resin compositions (Examples 1-1 and 1-6) as themodeling material according to the present invention is superior to theresin compositions (Comparative Examples 1-2 and 1-4JHH ) as thecomparative modeling material because the modeling material is less aptto compatibilize and does not intermix with the resin composition as thesupporting material and it is made possible to inhibit the swellingdeformation of the cured product, the decline in various physicalproperties, the variation of working accuracy, and the like untilcompletion of curing since there is almost no intermixed part of themodeling material and the supporting material.

INDUSTRIAL APPLICABILITY

In the modeling material according to the present invention constitutinga two-pack photocurable resin composition for ink-jet three dimensionalprinting method, there is very little swelling due to water or moistureabsorption or very little deformation due to moisture absorption onphotocuring and after curing, and moreover, the photocured product ofthe supporting material is excellent in solubility in water and is easyto remove after photofabrication, and the resulting photofabricationmodel is excellent in working accuracy and mechanical properties, andtherefore, the two-pack photocurable resin composition can be suitablyused as a material for the production of stereo models and is extremelyuseful.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 Personal computer (PC)    -   2 Three-dimensional modeling apparatus    -   21 Modeling table movable in z-direction    -   22 Printer head for modeling material    -   23 Printer head for supporting material    -   24 Roller    -   25 UV Light source    -   26 Printer head module    -   27 Cartridge containing modeling material    -   28 Cartridge containing supporting material    -   29 Feed pump    -   30 Feed pump

The invention claimed is:
 1. A supporting material used in ink jet threedimensional printing method where discharging of a modeling materialfrom a printer head for modeling material and discharging of asupporting material from a printer head for supporting material arerepeated for the formation of layers on a modeling table to shape athree-dimensional fabrication product formed of a photocured product ofthe modeling material and a photocured product of the supportingmaterial, and the photocured product of the supporting material isdissolved and separated from the photocured product of the modelingmaterial to extract the photocured product of the modeling material byimmersing the three-dimensional fabrication product in water, whereinthe supporting material contains a water-soluble monofunctionalethylenically unsaturated monomer (F), an alkylene oxide adduct (G), anda photopolymerization initiator (D), wherein said alkylene oxide adduct(G) having a number average molecular weight of from 100 to 5,000 andbeing a water-soluble compound, and said alkylene oxide adduct iscompatible with the water-soluble monofunctional ethylenicallyunsaturated monomer (F), and wherein the alkylene oxide adduct (G)within the photocured product of the supporting material being solublein water and not compatible with a photocured product of (F) and thecontent of (F) is 3% to 45% and the content of (G) is 50% to 95%, on thebasis of the weight of the supporting material.
 2. The supportingmaterial according to claim 1, wherein the photopolymerization initiator(D) is a water-soluble photopolymerization initiator.
 3. The supportingmaterial according to claim 1, wherein the photocured product of thesupporting material has a durometer hardness of 17 to 35 HDA.
 4. Thesupporting material according to claim 1, wherein (G) further compriseswater.
 5. The supporting material according to claim 1, wherein thephotocured product of the supporting material is dissolvable in waterand only the photocured product of the modeling material is extracted byimmersing the three dimensional fabrication product in water.